Vol. 1, Issue 1 (March 2001)

This page is brought to you with the co-operation of the Alberta Research Council and Alberta Agriculture, Food & Rural Development


Reports on trap catches in the Edmonton area indicate up to 15 thrips/sticky trap being caught near New Guinea Impatiens. Tomato spotted wilt tospovirus (TSWV) has been observed on begonias and impatiens. Symptoms to look for include necrotic lesions, ring spots or light colored mosaic on young leaves. Remember, thrips transmit tospoviruses that include TSWV and impatiens necrotic leaf spot virus (INSV). Check for thrips in your crops now. Tapien blue verbena flowers have been observed to be very attractive to thrips and could serve as an indicator plant for thrips.

Fungus Gnats

We have observed 15-20 fungus gnats caught in our traps. Populations are expected to increase with plant growth. Good sanitation is important to control fungus gnats.


We have so far caught about 5 whiteflies per trap close to Fuchsia plants. Continue monitoring in your greenhouse for these insects. It is very important to act quickly when they are detected, especially if you are using Encarsia formosa for control.

Spider mites

We have not detected any so far in our research greenhouses.


None detected, but watch your pepper plants closely for the first sign of aphids. Is there an upper limit to look for when considering whether to take action for controlling pests? Green houses are different and the crops grown vary tremendously. Growers and their markets also differ in the amount of damage they tolerate. Growers are therefore encouraged to establish their individual upper limits for these pests based on their own circumstances.